In a burner apparatus such as a water heater and room warming device, flammable gas or vaporized kerosene is fed through a proportional direction valve in response to a blower condition signal at the time of ignition.
At this time, the proportional directional valve determines the feeding amount of fuel in response to a heat adjustment operation. On the other hand, a thermal sensor is provided to detect the condition of flame so as to control the blower in association with the output from the thermal sensor.
In this instance, the proportional directional valve and the blower are individually controlled, so that when changing the feeding amount of air, the blower is controlled through the output of the thermal sensor in response to the heat adjustment operation. This results in very slow response of the blower to the heat adjustment operation. With this slow response the amount of air flow supplied becomes short in comparison with fuel gas so that normal combustion is hindered to generate toxic exhaust gas such as, for example, carbon monoxide.